Apparatus for electrical precipitation of suspended material from gases



Jan. 12 1926. 1,569,492

G. H. HQRNE APPARATUS FOR ELECTRICAL PRECIPITATION 0F SUSPENDED MATERIAL FROM GASES Filed April 13, 1925 2 Sheets-Sheet l INVENTOR GPO/y HID/77e @www ATTORNEY G. H. HORNE med April 13 2 sheets-sheet 2 F/ia. /3

l INVENTOR 10a/ye bf. Hor/7e Jan. 12 1926.

APPARATUS PoR ELECTRICAL PRECIPITATION 0F SUSPENDED MATERIAL FROM GAsEs and of the adjacent Patented Jian. 12,; 1926.

UNITED STATE-s- GEORGE .n BORNE, OP

FORMIA.

PATENT OFFICE.

GLENDALE, CALIFORNIA, ASSICNOR To INTERNATIONAL PRE- CIPITATION COMPANY, OE Los ANGELES, CALIFORNIA, A CORPORATION OE CALI-l APPARATUS POR ELECTRICAL PRECIPITATION OE SUSPENDED MATERIAL EROM GASES.

Application filed April 13,

T o all whom t may concern Be it known that I, GEORGE H. HORNE, a citi/.en of the United States, residing at Glendale, county of Los Angeles, State of California, have invented a new and useful Apparatus for Electrical Precipitation of Suspended Material -from Gases, of which the following is a speciication.

This invention relates to apparatus for electrical precipitation of suspended materials such as' dust, fume or mist from 'gases containing the vsame and particularly to apparatus for this purposein which the collecting electrodes are formed of semi-con-A ducting material such as concrete and /are provided with metallic conducting and reenforcing vmembers embedded therein.

An important object of the present invention is to provide an advantageous relative arrangement of said embedded conducting and re-enforcing members with respect to the discharge electrode means so as to simplify the construction and improve'the operation of the precipitator. My invention may be applied in connection with a collecting electrode of the above type consisting either of an integrat plate or built up of sectional units but certain advantages of the construction herein described are more fully realized. in the case of a sectional construction than in an integral construction as will be pointed out more Jfully hereinafter.

The accompanying drawings illustrate embodiments of my invention and referring thereto:

Fig. 1 is a longitudinal vertical section Ot an electrical precipitator embodying my invention and provided with sectional collecting electrodes.

Fig. 2 is a transverse vertical section of the form of the invention shown in Fig. 1. r

Fig. 3 is a partial horizontal vsection of one of the collecting electrodes shown in Fig. 1

discharge electrodes.

Fig. 4 is a partial side elevation of one of said collecting electrodes and the adjacent discharge electrodes.

Fig. 5 is a partial `side elevation iof a collecting electrode in which the metallic reenforcing and conductingmembers are not metallically grounded. p

Fig. G is a partial horizontal section of the collecting electrodes shown in Fig. 5

1925. serial-N0. 22,847.

andthe adjacent discharge electrodes.

.Fig 7 is an enlarged partial side elevation'ofthe electrode means shown in Fig. 5. F 1g. 8 is aside elevation of an integral collecting electrode together `with thefadjacent discharge electrode means adapted for use 1n a precipitator of the type shown in Fig. 1. i

Fig. 9 is a partial longitudinal vertical section of the collecting electrode shown in- Fig. 8.

Fig. 10 is a longitudinal ver-tical. section 'of an electrical precipitator sTroWing another embodiment of my invention.

Fig. 11 is a transverse section ot the electrical precipitator shown in Fig. l0.

l Fig. 12 is an enlarged partial side elevation of one of the collecting electrode means shown 1n Fig. 10 together with the adjacent discharge electrode members.

- Fig. 13 is a horizontal section Online 12.#13 in rig. 12.

lin the form of the invention shown in Fig. 1 the precipitator chamber or housing 1s indicated at 1 and is shown as provided with suitable inlet means 2 and outlet means 3 tor passage of gas therethrough and with suitablemeans atV the bottom of said cham-y ber such as hopper 4 adapted to receive the precipitated material. Any suitable means may be provided for removing such material from said hopper. The above described structure including the precipitator chamber and inlet and outlet and material-receiving means may be formed of any suitable maf. terial and in some cases may advantageously be constructed as shown of concrete or similar material. located a plurality of discharge electrode elements 5 and collecting electrode means 64 The discharge electrode elements 5 may consist of wires or small rods ofrelativelysmall cross-section and therefore of relatively small surface area and sharp surface curvature and in this caseare shown suspended vertically within the precipitator chamber. Any suitable means may be employed trode elements such ing rods 8 resting on end frames comprising horizontal members 9 and vertical members 1()v and said end frames being supported in turn by bus bars 11 resting for supporting said discharge elecas horizontal support- Within said chamber 1 are kon suitable insulating supports 12. Tensioni'ng means such as weights 13 may also be provided at the lower ends of said discharge electrode elements for causing said elements to hang in the proper position and suitable means such as bars 14 may also be mounted on the above described end frames and adapted to aline and space said tensioning means and discharge electrode elements.

' Each collecting electrode 6 comprises a plurality of horizontal sections 16 mounted one above another so as to form a substantially continuous collecting electrode plate. 1 prefer to provide at the bottom of each collecting electrode a base section 17 which is somewhat longer than thefremaining sections and is adapted to rest at its outer ends upon suitable supporting means such as ledges 18 formed in the precipitated housing and to support the upper sections 16 of the collecting electrode. Said sections 16 may be alined and held in position at their ends by suitable supporting frame means such as channel irons 19 and supported for example by suitable means such as lateral beams or channel irons 20. The sections 16 of the collecting electrode plates are formed of suitable semi-conducting material such as Portland cement concrete, terracotta, or other plastic composition or cementitious material, which has a relatively low electrical conductivit and they may be held together at their adi'oining edges by means of tongue and groove joints and also if desired by means of mortar or cement grout. In order vto strengthen and re-enforce said sections and also cause uniform distribution of electrical potential to all parts thereof I prefer to provide metallic conduct-ing and re-enforc ing members 22 extending horizontally with-l in said sections and metallically grounded, for example by connection with the metallic supporting members 19.v Said conducting and re-enforcing members may consist of wires or of smooth or twisted rods and said rods may be either round or square or of any other suitable shape. The base section 17 may also be provided with suitable reenforcing and conducting means indicated at 23 and said means may also be grounded by connection with the metallic frame members 19. It is not necessary inl all cases however that the metallic re-enforcing and conducting means 22 as well as 23 be in metallic connection with the ground and in some cases I may prefer to eliminate such connection as shown in Figs. 5 to 7. 1n such casos the members 22 stop a short distance from the ends of the sec- Vtions 16 and are therefore out of connection with the supporting members 19 and the reenforcing means 23 are similarly out of con-` nection with said means 19. Or if desired the re-enforcmg and conductmg members tential of the earth.

22 and 23 may be connected to said metallic supporting means 19 as in the form first described, but said supporting means may not be`metallically` grounded, but may be grounded only through the concrete or other semi-conducting material of which the precipit-atorhousing is constructed. t

Any suitable spacing may be provided between the discharge electrode elements 5 and also between the embedded conduct-ing and re-enforcing members 22, for example as shown the spacing between the said members 22 may be somewhat greater than the spacing between the discharge electrodeelements 5 and'it should be noted that there need be no definite inter-relation between the respective spacings of said members.

The discharge electrode system may be connected for example through wire indicated at 25 to one side of a source of high tension current, either alternating or direct, but preferably rectified alternating current,

-the other side of which source is grounded.

Said source of high tension current is preferably adapted to maintain a potential difference between the discharge electrodes and the grounded collecting electrodes of from say 15,000 to 100,000 volts. The exact voltage'required in any case depends upon the spacing of the electrodes, the nature 0f the gas being treated, and upon other conditions. The collecting electrode system is preferably grounded as indicated at being actually accomplished for example by connecting a grounded wire to a suitable part of the metallic supporting means for the collecting electrodes. When so grounded it will be seen that in in Figs. 1 to 4t the re-enforcing and conducting members22 are in direct metallic connection with the ground so that all portions of the collecting electrodes are maintained at all times at substantially the po- In the form of the invention shown in Figs. 5 to 7 on the other hand the re-enforcing and conducting members 22 are not in direct metallic connection with the ground but are only in connection therewith through the high resistance or semicondueting material of the electrode between the ends of said members 22 and the side frames 19. This may be of advantage in some cases in that while the conducting members 22 serve to maintain all portions of the collecting electrode at substantially uniform potential the interposition of the high resistance material at the point above mentioned between said conducting members and the ground prevents the flow of'sulficient current to or from any portion of one of sai-d conducting members to cause disruptive discharge, as may be the case whensaid members are in direct metallic connecticn with the ground. It should be noted however that the members 22 serve in either 26, said grounding the forms shown 4 Iit ease not only to mechanically re-enforce the sections 16 of the collecting electrodes but also to maintain substantially uniform distribution of electrical potential at the sur face thereof.

In the operation of this form of the invention the electrode system is energized by connection to the source of high tension current as above described and by reason of the relatively small surface area and sharp curvature of the discharge electrodes-and the relatively extended area of the collecting electrodes, a silent discharge d is produced from the former to the latter. rlhe gas to be treated is passed through the chamber 1 so as to flow substantially hor'zontally between the discharge electrodes and the collecting electrodesC Under the action of the electrical discharge the suspended particles carried by the gas become charged and are attracted to the collecting electrodes 6. The material so precipitated eventually falls off the collecting electrodes by gravity and collects in the hopper 4f at the bottom of the preeipitator from which it may be removed in any suitable Jmanner either continually or from time to time. necessary the collecting electrodes may be jarred or rapped from time to time to dislodge deposited material therefrom but it has beenfound with semi-conducting Amaterials such a'siconcrete that the deposited.

material adheres thereto in a relatively loose manner and therefore falls off by. its own weight before it becomes thick enough to seriously impair the effective operation of the precipitator.

@ne advantage of the above described construction 'is that there need be no denite relation between the spacing of the discharge electrode elements 5 and the spacing of the re-enforcing members 22. 'lhis form 4of construction is .therefore to be distinguished from previously described constructions 1n which the collecting electrodes werev formed of semi-conducting material and were provided with re-enforcing and conducting members extending parallel to the vdischarge electrode elements. In those cases it has beenl necessary. j to f preserve throughout the precipitator a substantiallyuniform relation between the spacing'of the discharge electrode elements and the spacing of the re-enforcing and conducting members in order that-none of the embedded conducting members shall bejappreciably closer to an adjacentdischarge .electrode element than are any of the other embedded conducting members, so as to prevent concentration of the electrical field in the portion of the collecting electrode adjacent said embedded member. Such accurate positioning of the electrodes isA not always practicable,

in some cases, and 1n such cases, the use of my form ofconstruction 1s deslrable, as with llf .desired orv foundv fective operation of the precipitator to pro-` vide a different spacing between the einbedded conducting members 22 and between the collecting electrode elements For example the form of the construction shown in Fig. 1 in which the embedded conducting members are spaced at a somewhat greater distance apart than the discharge electrode elements may be very effective in some 'cases'. ilhe spacing between adjacent embedded members 22 may for example be approximately one and one half times the spacing between adjacent discharge el'ec-l trode elements 5.

A further advantage of this form of construction arises from the fact that it is often necessary in construction of electrical precipitators to make the collecting electrodes 'relatively high and narrow and in such cases it is much more .,desirable, when a sectional type of collecting electrode is used, to construct the plates of horizontal sectionsl one above another rather than to form said plates of a plurality of vertical sections one beside another. lt is therefore often unavoidable when using a sectional construction of the collecting electrode plates that the breaks between adjacent sections extend horizontally as indicated at 28 in Fig. 1. lt has also been found in certain eases very ico undesirable to have the embedded re-enforcing and conducting members extending across said.

throughout vsubstantially 'the entire length` of the collecting electrode without crossing any joints between sections, and at the same time have the collectingv electrode Lsections extend horizontally one above another, that each of said sections be provided with one or 'more embedded re-enforcing and conducting .members extending horizontally within said section and substantially throughout the entire length thereof. It-

breaks between adjacent sec. tions because of the fact that said re-en-J has also been found however that it is much more advantageous to have the discharge electrode elements extend vertically rather than horizontally in many cases in which such sectional collecting electrode construction is used, due to the difficulty in preserving propel' alinement and ytensioning of horizontal discharge members of sufficiently small cross-section .to produce the most effective electrical discharge. The construction according to my invention in which the discharge electrode elements extend vertically and the embedded conducting members extend horizontally, therefore not only accomplishes the advantageous results above described of permitting the variation bctween the spacing of the discharge members and the embedded conductors and preventing concentration of lthe electrical field due to any one of said embedded conductors being closer to the discharge electrodes than the other embedded conductors, but also permits both the embedded conductors and the discharge electrode elements to extend in the most desirable direction for effective electrical precipitation.

' prise an integral plate of concrete or other semi-conducting material resting as before on base section 17 and supported in suitable frame means 19 at both sides. Said collecting electrode plate may advantageously be provided with horizontally extending embedded conducting and re-enforcing members 22 which may be metallically grounded as shown by connection to said side frames l5), or as above described may stopv at a slight distance from said side frames so as to be grounded only through the intervening portion of the semi-com'lucting material of the collecting electrode. It will be noted that in this form of the invention also the discharge electrode elements extend vertically while the embedded conductors extend horizontally so that there need be no definite relation between the spacing of said discharge electrode elements and said embedded conductors. The above mentioned advantages arising from this feature of the invention namely thefact that the spacing between the embedded conductors may be made somewhat greater than the spacing between the discharge electrode elements if desired and also that a failure to preserve uniform spacing between said einbedded conductors and uniform relation between the -said embedded conductors and said discharge electrode elements will not cause concentration of the electrical field at a portion of the collecting electrode o posite one of said embedded conductors w ich is closest to an adjacent discharge electrode element, are realized in-this form of construction as well as in the sectional construction rst described.

My invention is not limited to the above described forms of construction in which the discharge members extend vertically and the embedded conductors horizontally but it should be understood to include any construction in which said embedded conductors and discharge members extend transversely or at right angles to one another. -For example as shown in Figs. l0 to 13 inclusive the collecting electrode may be formed as an integral plate 6 of concrete or other semi-conducting material and the embedded conductors 22 may extend vertically therein while the discharge electrode members 5 extend horizontally. Said discharge.

electrode members may be supported by suitable frame means as shown resting on insulating supports 12 and said collecting electrode plates may be supported by means of channel irons or other suitable supporting members 3() extending along their upper edges and secured thereto in any suitable manner. Said supporting members 30 may in turn rest on supporting means such as Z-bars 3l at the top of the precipitator housing l. The collecting electrode plates 6 may be secured to and suspended from said supporting members 30 by means of beams or channel irons 32 at the bottom of said plates and tie-rods 33 at the edges of said plates and secured at their ends to supports 30 and 32. The supporting means 30, 32, and 33 therefore comprise a metallic conducting and supporting frame for said col-v lecting electrode plate and serve not only to support said plate but also to ground the same, for example through ground wire indicated at 2G. 'lhe embedded conductors 22 may as before be metallically grounded by connection at their ends to the frame members 30 and 32 or said embedded conductors may if desired stop somewhat short of said frame members so as to be in connection With the ground only through the intervening portion of thel semi-conducting material of the electrode. In either case however said members 22 serve to both mechanically re-enforce the collecting electrode plate and to maintain substantially uniform distribution of electrical potential to the collecting surfaces thereof. It will be observed that in this case as before the discharge electrode members and the embedded.

conductors extend perpendicular-ly to one another, and thaty consequently there need be no definite relation between the spacing of said members, for the reasons above mentioned, and the above described advantages arising from this fact are therefore realized.

LEESQAQQ 'lhe electrical connections and the operation of the two last-described forms of my invention, provided with integral collecting electrodes, may be substantially the same as above described.

l/Vhat claim is:

l. ln an electrical preoipitator a collecting electrode `formed of semi-conducting material and provided with metallic members embedded therein and extending horizontally, and discharge electrode means adja` cent said collecting electrode means and cornprising a plurality of vertically extending members of relatively small cross-section.

2. ln an electrical precipitator a collecting electrode consisting of semi-conducting material and provided with a plurality of metallic members embedded therein and extending substantially throughout the length thereof, and discharge electrode means adjacent said collecting electrode and comprising a plurality ora members extending transversely to said embedded members.

3. ln an electrical precipitator a collecting electrode comprising a plate of semi-conducting material, grounded metallic frame means supporting said plate, embedded metallic members Within said plate, and connected at theirends to said metallic frame means and discharge electrode means mounted adjacent said plate and comprising a pluralityv of members extending transversely to said embedded members.

4. ln an electrical precipitatora collecting electrode comprising a plurality-of sections mounted one above another to term aplate, l

said sections being formed of semi-conducting material, metallic 4members embedded Within said sections and. extending horizontally therein, and discharge electrode means adjacent said collecting electrode and comprising a plurality vertically extending members.

loy

5. iin an electrical orecipidnator a collecting electrode plate comprising a. plurality ot super-posed sections of semi-conducting material, grounded metallic supporting meansA engaging said sections at their ends, metal- `1 lic members embedded Within said sections and extending horizontally therein and eony nected at their ends to said metallic supporting means, and discharge electrode means comprising a plurality of members eX- tending vertically adjacent said collecting electrode plate.

6. ln anelectrical precipitator a collecting electrode plate formed of semi-conducting material, a plurality1 of metallic members embedded Within said material and extending parallel to one another, and discharge electrode means comprising a plurality of members extending transversely to said em-A bedded inembers, the spacing between'said embedded members being unequal to thel pacing between the members of said dislcharge electrode means.

lin testimony whereof l have hereunto subscribed my -name this tenth day of March,1925.

. GERGE H. HORNE. 

